VCHIQ doesn't work on ARM64

[mariobalanica]

The ACT led starts blinking 8 times in a pattern when the driver is loaded, indicating a VCHI error.
It doesn't respond to any commands afterwards (tested using some of the ported userland apps here: https://github.com/ms-iot/userland)

I recall seeing the hello_jpeg sample work on ARM32 (RPi 3), but subsequent runs resulted in either the driver hanging or a bug check.

[driver1998]

The VCHIQ initialization issue with blinking ACT should be resolved with 051a7c8, more validation needed.

[dongwei67]

This device shows up with yellow bang in Windows (installed via WoR) on RPi 400